1,721,102 research outputs found
Early transition metal complexes of polydentate and macrocyclic thio- and seleno-ethers
No full textRecent work on the syntheses, structures and properties of complexes of polyclentate and macrocyclic thio- and seleno-ether ligands with Groups 3-6 metals in positive oxidation states (greater than or equal to 3) is described
Di-mu-chloro-bis heptaaquacerium(III) tetrachloride
No full textThe structure of [(H2O)(7)CeCl2Ce(H2O)(7)]Cl-4, or [Ce2Cl2(H2O)(14)]Cl-4, has been redetermined at 120 K and rerned in space group P(1) over bar (No. 2) with a centrosymmetric cation. Refinements in space groups P(1) over bar and P1 (No. 1) are discussed
Catalytic air oxidation of tertiary arylphosphines in the presence of tin(IV) iodide
No full textArylphosphines including Ph3P, o-C6H4(PPh2)(2) and Ph2PCH2CH2PPh2 are cleanly and quantitatively converted into the corresponding phosphine oxides on reaction with dry air or dioxygen in CH2Cl2 solution in the presence of catalytic amounts of SnI4
Bis(nitrato-κ<sup>2</sup>O,O')(1,4,7,10,13-pentaoxacyclopentadecane)calcium(II)
No full textThe crystal structure of the title compound, [Ca(NO3)2-(C10H20O5)], at 120 K contains discrete molecules with nine coordinate Ca atoms. There are two molecules in the asymmetric unit, related by a pseudo-inversion centre. The crown bonds through five O atoms [Ca—O = 2.464 (2)–2.567 (2) A ° ] and the nitrates are bidentate [Ca—O = 2.444 (2)–2.588 (2) A ° ]. The structure is a polymorph of a previously reported room-temperature form
(Ethanol-O)tris(nitrato-O,O')bis(triphenylphosphine oxide-O)cerium(III)
No full textThe title compound, [Ce(NO3)(3)(C2H6O)(C18H15OP)(2)], contains discrete molecules with nine-coordinate Ce atoms having all nitrate groups bonded as symmetrical bidentate ligands [Ce-O(P) 2.369 (2) and 2.385 (2), Ce-O(N) 2.549 (3)-2.596 (3) and Ce-O(Et) 2.515 (3) Angstrom]
Synthesis, spectroscopic, and structural studies on transition metal complexes involving homoleptic tripodal selenoether and telluroether coordination
No full textThe reaction of [MCl2(NCMe)(2)] (M = Pd or Pt) with 2 molar equiv of MeC(CH2ER)(3) (E = Se, R = Me; E = Te, R = Me or Ph) and 2 molar equiv of TlPF6 affords the his ligand complexes [M{MeC(CH2ER)(3)}(2)][PF6](2). The crystal structure of [Pt{MeC(CH2SeMeMe)(3)}(2)][PF6](2) (C16H36F12P2PtSe6, a = 12.272(10) Angstrom, b = 18.563(9) Angstrom, c 15.285(7) Angstrom beta = 113.18(3)degrees monoclinic, P2(1/n), Z = 4) confirms distorted square planar Se-4 coordination at Pt(II), derived from two bidentate tripod selenoethers with the remaining arm not coordinated and directed away from the metal center. Solution NMR studies indicate that these species are fluxional and that the telluroether complexes are rather unstable in solution. The octahedral bis tripod complexes [Ru{MeC(CH2SMe)(3)}(2)][CF3-SO3](2) and [Ru{MeC(CH2TePh)(3)}(2)][CF3SO3](2) are obtained front [Ru(dmf)(6)][CF3SO3](3) and tripod ligand in EtOH solution. The thioether complex (C18H36F6O6RUS8 a = 8.658(3) Angstrom, b = 11.533(3) Angstrom, c 8.659(2) Angstrom, alpha = 108.33(2)degrees, beta = 91.53(3)degrees, gamma 106.01(2)degrees triclinic, P1, Z = 1) is isostructural with its selenoether analogue, involving two facially coordinated trithioether ligands in the syn configuration. NMR spectroscopy confirms that this configuration is retained in solution for all of the bis tripod Ru(II) complexes. These low-spin d(6) complexes show unusually high ligand field splittings. The hexaselenoether Rh(III) complex [Rh{MeC(CH2SeMe)(3)}(2)][PF6](3) was obtained by treatment of [Rh(H2O)(6)](3+) with 2 molar equiv of MeC(CH2SeMe)(3) in aqueous MeOH in the presence of excess PF6- anion, while the iridium(III) analogue [Ir{MeC(CH2SeMe)(3)}(2)][PF6](3) was obtained via the reaction of the Ir(I) precursor [IrCl(C8H14)(2)](2) with the selenoether tripod in MeOH/aqueous HBF4. NMR studies reveal different invertomers in solution for both the Rh and Ir species. The Cu(I) complexes [Cu{MeC(CH2ER)(3)}(2)]PF6 were obtained from [Cu(NCMe)(4)]PF6 and tripod ligand in CH2Cl2 solution. The corresponding Ag(I) species [Ag({MeC(CH2TeR)(3)}(2)]CF3SO3 (R = Me or Ph) were obtained from Ag[CF3SO3] and tripod telluroether. In contrast, a similar reaction with 2 molar equiv of MeC(CH2SeMe)(3) afforded only the 1:1 complex [Ag{MeC(CH2SeMe)(3)}]CF3SO3. The structure of this species (C9H18AgF3O3SSe3, a = 8.120(3) Angstrom, b = 15.374(3) Angstrom, c = 14.071(2) Angstrom, beta = 93.86(2)degrees, monoclinic, P2(1/n), Z = 4) reveals a distorted trigonal planar geometry at Ag(I) derived from one bidentate selenoether and one monodentate selenoether. These units are then linked to adjacent Ag(I) ions to give a one-dimensional linear chain cation
Synthesis, characterisation and reactions of ruthenium(II) complexes based upon RuL3 (2+) (L-3 = tripodal triseleno- or tritelluro-ether) fragments. Structures of RuCl2(PPh3){MeC(CH2SeMe)(3)} and RuCl2(dmso){MeC(CH2SeMe)(3)}
No full textThe reaction of [RuCl2(PPh3)(3)] with tripodal Group 16 donor ligands L-3 {MeC(CH2EMe)(3) (E=Se or Te) and MeC(CH2TePh)(3)} gave [RuCl2(PPh3)L-3] complexes which have been characterised by elemental analysis, IR and NMR spectroscopy and ES+ mass spectrometry. The structure of [RuCl2(PPh3){MeC(CH2SeMe)(3)}] reveals a distorted octahedral geometry with a facially co-ordinated triselenoether. The reaction of [RuCl2(dmso)(4)] with L-3 gave [RuCl2(dmso)L-3] which have similarly been characterised, including a crystal structure of [RuCl2(dmso){MeC(CH2SeMe)(3)}], which is fac-octahedral with S-bonded dmso. The [RuCl2(dmso)L-3] species react with Ag[CF3SO3] in MeCN to produce [Ru(MeCN)(3)L-3](2+) {L-3=MeC(CH2SeMe)(3) or MeC(CH2TePh)(3)}. The MeCN is labile and readily replaced by a second tridentate ligand to give mixed tripod ligand complexes including [Ru{MeC(CH2SMe)(3)}{MeC(CH2SeMe)(3)}][CF3SO3](2) and [Ru{MeC(CH2SeMe)(3)}{MeC(CH2TePh)(3)}][CF3SO3](2). Attempts to generate hydride species by reaction of [Ru(MeCN)(3)L-3](2+) with NaBH4 in ethanol bring about decomposition
Synthesis and properties of thallium(III) periodate
No full textThe reaction of [T1(H2O)(6)](3 +) with H5IO6 in aqueous acid solution over a range Tl-5(IO6)(3), which has been characterised by analysis, IR and UV-Vis spectroscopy The compound is amorphous, but I K- and Tl L-III edge EXAFS studies identify IO6 and TlO6 as the structural units present and a possible structure is proposed. The Tl(III)-IO6 system is compared with literature data on gallium and indium periodate complexes. The Tl(III)-IO6 system is compared with literature data on gallium and indium periodate complexes
Synthesis and properties of the first series of mixed thioether/telluroether macrocycles
No full textThe preparations of the first examples of mixed thioether/telluroether macrocycles, [9]aneS(2)Te (1,4-dithia-7-telluracyclononane), [11]aneS(2)Te (1,4-dithia-8-telluracycloundecane), [12]aneS(2)Te (1,5-dithia-9-telluracyclododecane) and [14]aneS(3)Te (1,4,7-trithia-11-telluracyclotetradecane) via a 'disguised dilution' method are described, together with the crystal structure of [Ag([11]aneS(2)Te)]BF4 which serves to authenticate the macrocyclic ligand
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